Amine salts of phosphinic acid or carboxylic acid esters thereof as antioxidants for organic materials



Uflited States Patent US. Cl. 25232.5 7 Claims ABSTRACT OF THE DISCLOSURE Stabilizing hydrocarbon oil, grease or synthetic lubricant against oxidative deterioration by incorporating therein an amine salt of bis-'(hydroxyalkyl)-phosphinic acid or ester thereof.

CROSS REFERENCE TO RELATED APPLICATIONS This is a division of application Ser. No. 493,918, filed Oct. 7, 1965 and now abandoned.

DESCRIPTION OF THE INVENTION This invention relates to the stabilization of hydrocarbon oil, grease or synthetic lubricant by incorporating therein a stabilizing concentration of a novel additive.

The novel additive of the present invention is an amine salt of bis-(hydroxyalkyD-phosphinic acid and may be illustrated by the following general formula:

where R and :R are alkyl, R and R are hydrogen or alkyl and R is alkyl or alkenyl. In a particularly preferred embodiment R and R are alkyl containing from 1 to about 6 carbon atoms, R and R are hydrogen or alkyl containing from 1 to about 12 carbon atoms and R is alkyl containing from about 4 to about 50 carbon atoms and still more preferably from about 8 to about 40 carbon atoms. The number of carbon atoms in the alkyl groups will be selected with reference to the use of the additive. For example, when the additive is used in organic substrates and particularly hydrocarbon oils, a higher number of carbon atoms is desired in order to insure ready solubility of the additive in the substrate.

The additive illustrated in the above formula is prepared in any suitable manner. Any suitable bis-(hydroxyalkyl)- phosphinic acid is used and may be obtained from any suitable source or prepared in any suitable manner. For example, bis-(hydroxymethyl)-phosphinic acid is available commercially. It has a molecular weight of 126 and solidifies to a waxy solid at a temperature of about C. Any suitable amine is used in preparing the salt and may be a primary, secondary or tertiary amine. In a preferred embodiment the amine is an alkyl amine in which the alkyl group or groups may be of primary, secondary or tertiary configuration. Preferred primary amines in- 3,542,679 Patented Nov. 24, 1970 elude those in which R and R in the above formula are hydrogen and R is an alkyl of from 4 to 50 carbon atoms and more particularly from 8 to 40 carbon atoms. Illustrative primary amines in this embodiment include butyl amine, pentyl amine, hexyl amine, heptyl amine, octyl amine, nonyl amine, decyl amine, undecyl amine, dodecyl amine, tridecyl amine, tetradecyl amine, pentadecyl amine, hexadecyl amine, heptadecyl amine, octadecyl amine, nonadecyl amine, eicosyl amine, heneicosyl amine, docosyl amine, tricosyl amine, tetracosyl amine, pentacosyl amine, hexacosyl amine, heptacosyl amine, octacosyl amine, nonacosyl amine, triacontyl amine, etc. It is understood that the alkyl group may be of primary, secondary or tertiary configuration. Specifically included are beta-alkyl amines, also referred to as beta-amines, in which the alkyl group is attached at the second or beta carbon atom to the nitrogen atom.

In some cases, high boiling primary amines are available commercially, generally at a lower cost, as mixtures of amines. For example, one such mixture available commercially is marketed as Primene 81 R and is said to comprise a mixture of tertiary alkyl amines containing from 12 to 14 carbon atoms in the alkyl group. This mixture has a molecular weight principally of -213, 5-90% boiling range at 760 mm. of 221-238 C., a specific gravity at 25 C. of 0.813, a density at 25 C. of 6.8 pounds per gallon and a refractive index at 25 C. of 1.423. Another mixture is marketed commercially as Primene JM-T and is said to comprise a mixture of tertiary alkyl amines containing 18 to 22 carbon atoms per molecule. This mixture has a molecular weight principally of 269-325, a neutral equivalent of 315, a specific gravity at 25 C. of 0.840, a density at 25 C. of 7.0 pounds per gallon and a refractive index at 25 C. of 1.456

Illustrative secondary amines include dimethyl amine, diethyl amine, dipropyl amine, dlibutyl amine, dipentyl amine, dihexyl amine, diheptyl amine, dioctyl amine, dinonyl amine, didecyl amine, diundecyl amine, didodecyl amine, ditridecyl amine, ditetradecyl amine, dipentadecyl amine, dihexadecyl amine, dihep'tadecyl amine, dioctadecyl amine, dinonadecyl amine, dieicosyl amine, etc., as Well as mixed secondary amines in which the alkyl groups are different. Illustrative examples of mixed secondary amines include methylethyl amine, methylpropyl amine, methylbutyl amine, methylpentyl amine, methylhexyl amine, methylheptyl amine, methyloctyl amine, methylnonyl amine, methyldecyl amine, methylundecyl amine, methyldodecyl amine, methyltridecyl amine, methyltetradecyl amine, methylpentadecyl amine, methylhexadecyl amine, methylheptadecyl amine, methyloctadecyl amine, methylnonadecyl amine, methyleicosyl amine, etc., ethylpropyl amine, ethylbutyl amine, ethylpentyl amine, ethylhexyl amine, ethylheptyl amine, ethyloctyl amine, ethylnonyl amine, ethyldecyl amine, ethylundecyl amine, ethyldodecyl amine, ethyltridecyl amine, ethyltetradecyl amine, ethylpentadecyl amine, ethylhexadecyl amine, ethylheptadecyl amine, ethyloctadecyl amine, ethylnonadecyl amine, ethyleicosyl amine, etc., propylbutyl amine, propylpentyl amine, propylhexyl amine, propylheptyl amine, propyloctyl amine, propylnonyl amine, propyldecyl amine, propylundecyl amine, propyldodecyl amine, propyltridecyl amine, propyltetradecyl amine, propylpentadecyl amine, propylhexadecyl amine, propylheptadecyl amine, propyloctadecyl amine, etc., butylpentyl amine, butylhexyl amine, butylheptyl amine, butyloctyl amine, butylnonyl amine, butyldecyl amine, butylundecyl amine, butyldodecyl amine, butyltridecyl amine, butyltetradecyl amine, butylpentadecyl amine, butylhexadecyl amine, etc., pentylhexyl amine, pentylheptyl amine, pentyloctyl amine, pentylnonyl amine, pentyldecyl amine, pentylundecyl amine, pentyldodecyl amine, etc. It is understood that the specific amines set forth above are illustrative and that other suitable mixed secondary amines may be employed. Also it is understood that the alkyl groups may be of primary, secondary or tertiary configuration, including beta-amines.

Illustrative tertiary amines include trimethyl amine, triethyl amine, tripropyl amine, tributyl amine, tripentyl amine, trihexyl amine, triheptyl amine, trioctyl amine, trinonyl amine, tridecyl amine, triundecyl amine, tridodecyl amine, tritridecyl amine, tritetradecyl amine, tripentadecyl amine, trihexadecyl amine, triheptadecyl amine, trioctadecyl amine, trinonadecyl amine, trieicosyl amine, etc. In another embodiment the tertiary amine is a mixed amine in which two of the alkyl groups are the same and the third alkyl group is different or those in which all of the alkyl groups are different.

Generally there are available commercially various tertiary amines in which two of the alkyl groups contain from 1 to 4 and possibly from 1 to 12 carbon atoms and the third alkyl group is of longer chain and contains from 4 to 50 and more particularly from 8 to 40 carbon atoms. Because of the ready availability of such tertiary amines, they advantageously are used in preparing the salt of the present invention. For example, one such tertiary amine is available commercially as Armeed DMHTD and is dimethyloctadecyl amine. Other amines of this type are dimethyldodecyl amine, dimethyltridecyl amine, dimethyltetradecyl amine, dimethylpentadecyl amine, dimethylhexadecyl amine, dimethylheptadecyl amine, dimethylnonadecyl amine, dimethyleicosyl amine, dimethyldocosyl amine, dimethylheneicosyl amine, dimethyltricosyl amine, dimethyltetracosyl amine, dimethylpentacosyl amine, dimethylhexacosyl amine, dimethylheptacosyl amine, dimethyloctacosyl amine, dimethylnonacosyl amine, dimethyltriacontyl amine, etc. Other mixed tertiary amines include methylbutyldodecyl amine, methylpentyldodecyl amine, methylhexyldodecyl amine, methylheptyldodecyl amine, methyloctyldodecyl amine, methylnonyldodecyl amine, methyldecyldodecyl amine, methylundecyldodecyl amine, etc. Here again it is understood that the above specific compounds are illustrative only and that other mixed tertiary amines may be used to form the salt of the present invention. Also it is understood that the alkyl groups may be of primary, secondary and/or tertiary configuration whenever the steric considerations permit such use.

While the alkyl monoamines are preferred for use in forming the salt of the present invention, it is understood that polyamines may be used in preparing the salt. Illustrative polyamines include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, etc., and corresponding alkylene polyamines in which the alkylene group is selected from propylene, butylene, pentylene, hexylene, etc. However, to insure solubility in the substrate when the composition of matter is used as an additive, the polyamine preferably contains at least 10 and more particularly at least 20 carbon atoms and thus the polyamines preferably are N-alkyl, N,N-dialkyl, N,N,N'-trialkyl or N,N,N,N'-tetraalkylalkylene polyamines in which the alkylene group or groups each contains from 4 to 50 carbon atoms and wherein said alkyl group or groups may be primary, secondary or tertiary, including one or more beta-amine configurations.

In general it is preferred that R, in the above general formula is an alkyl group. However, in another embodiment of the invention, R may be an alkenyl group, particularly when it is of high molecular weight. Accordingly, illustrative primary amines comprise dodecenyl amine, tridecenyl amine, tetradecenyl amine, pentadecenyl amine, hexadecenyl amine, heptadecenyl amine, octadecenyl amine, nonadecenyl amine, eicosenyl amine, etc. Illustrative secondary amines include methyldecenyl amine, methylundecenyl amine, methyldodecenyl amine, methyltridecenyl amine, methyltetradecenyl amine, methylpentadecenyl amine, methylhexadecenyl amine, methylheptadecenyl amine, methyloctadecenyl amine, methylnonadecenyl amine, methyleicosenyl amine, etc., similar secondary amines in which the methyl is replaced by ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, etc. Illustrative tertiary amines include dimethyldecenyl amine, dimethylundecenyl amine, dimethyldodecenyl amine, dimethyltridecenyl amine, dimethyltetradecenyl amine, dimethylpentadecenyl amine, dimethylhexadecenyl amine, dimethylheptadecenyl amine, dimethyloctadecenyl amine, dimethylnonadecenyl amine, dimethyleicosenyl amine, etc., and similar tertiary-amines in which one or both or the methyl groups are replaced by ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, etc. Still other tertiary amines include didecenylmethyl amine, diundecenylmethyl amine, didodecenylmethyl amine, ditridecenylmethyl amine, ditetradecenylmethyl amine, dipentadecenylmethyl amine, dihexadecenylmethyl amine, diheptadecenylmethyl amine, dioctadecenylmethyl amine, dinonadecenylmethyl amine, dieicosenylmethyl amine, etc., and similar compounds in which the methyl group is replaced by a higher molecular weight alkyl or alkylene group.

While the use of an aliphatic amine in preparing the salt is preferred, in another embodiment of the invention the amine used in preparing the salt may be a cyclic amine. Illustrative cyclic amines include aromatic amines such as aniline, methylaniline, dimethylaniline, diethylaniline, toluidine, xylidine, etc., as well as other primary, secondary or tertiary aromatic amines and these amines containing hydrocarbyl and particularly alkyl groups at tached thereto. In another embodiment the cyclic amine is a cycloalkyl amine and particularly cyclohexylamine, which again may be primary, secondary or tertiary amine and may contain hydrocarbyl and particularly alkyl groups attached to the nucleus.

When the salt is to be used as an insecticide, pesticide, fungicide, etc., it also may contain halogen. The halogen preferably is chlorine or bromine, but also may be fluorine or iodine, or mixtures thereof. The halogen may be attached to either the alkyl or cyclic moieties of the salt.

As hereinbefore set forth the amine used in preparing the salt will be selected with reference to the use of the additive. When used as an additive in organic substrates and particularly hydrocarbon oil, the alkyl group or groups should be of longer carbon chain length and preferably should contain from 8 to 40 carbon atoms or more per alkyl group.

The salt is prepared in any suitable manner and generally by commingling the amine and acid, preferably with intimate stirring. Although the mixing may be effected at ambient temperature, in order to facilitate formation of the salt it is preferred to heat the reaction mixture, usually at a temperature up to about 200 C. and preferably from about 75 to C. However, heating to an excessive temperature should be avoided in order not to cause chemical reaction between the acid and the amine which results in the liberation of water.

In general, the salt is prepared in the absence of a solvent. However, when desired, any suitable inert solvent may be used to facilitate mixing. As an alternative method, one or both of the acid and amine may be admixed previously with the solvent and then used in this manner to prepare the salt. Illustrative solvents include aromatic hydrocarbons, high boiling paraffinic hydrocarbons, etc.

The amine is used in a mole proportion of from 0.5 to 2 moles of amine per 1 mole of acid and preferably the amine and acid are used in equal mole proportions.

The salt formed from equal mole proportions of amine and acid is illustrated in the formula hereinbefore set forth. However, it is understood that the double salt and/ or polymers may be formed, particularly when the amine and acid are used in other than equal mole proportions.

As hereinbefore set forth, in another embodiment, the additive comprises an amine salt of an ester of bis-(hydroxyalkyl)-phosphinic acid. The ester may be a monoester, a polyester, or mixture thereof, depending upon whether a monocarboxylic acid or polycarboxylic acid is employed in forming the ester and upon the mole ratios of reactants used.

In this embodiment of the invention it is essential that the amine salt of the bis-(hydroxyalkyl)-phosphinic acid is first prepared and it is also essential that the amine used in preparing the salt is a tertiary amine. The tertiary amine will be selected from those hereinbefore set forth and the salt will be prepared in the same manner as described previously. The use of a tertiary amine in this embodiment serves to neutralize or tie up the active hydroxyl group attached to the phosphorous atom. This, in turn, permits reaction of the hydroxyalkyl group or groups to form the ester.

In a preferred embodiment a dicarboxylic acid or anhydride is used in forming the ester. The additive prepared from the dicarboxylic acid or anhydride is illustrated by the following general formula:

where R and R have the designation as hereinbefore set forth, R and R are hydrogen, alkyl, or alkenyl, R R and R are alkyl or alkenyl, n ranges from to about 10 and m is an integer of from 1 to about 10. In a particularly preferred embodiment R and R are akyl containing from 1 to 6 carbon atoms each, at least one of R and R is an alkyl or alkenyl group containing from 1 to 40 carbon atoms, at least 2 carbon atoms when alkenyl, and more particularly from about 8 to about 40 carbon atoms, R-; and R are alkyl containing from 1 to about 12 carbon atoms, R is an alkyl or alkenyl containing from 1 to about 40 carbon atoms and more particularly from 8 to about 40 carbon atoms, 11 ranges from 2 to 4 and m is an integer of 1 to 4.

Any suitable polycarboxylic acid is utilized in forming the salt and preferably comprises an aliphatic dicarboxylic acid. Illustrative dicarboxylic acids include oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, maleic, fumaric, itaconic, citraonic, mesaconic, etc. While the dicarboxylic acids are preferred, it is understood that polycarboxylic acids containing three, four, or more carboxylic acid groups may be employed. Furthermore, it is understood that a mixture of polycarboxylic acids and particularly of dicarboxylic acids may be used. A number of relatively inexpensive dicarboxylic acids comprising a mixture of these acids are marketed commercially under various trade names, including VR-l Acid, Dimer Acid, Empol 1022, etc., and these acids may be used in accordance with the present invention. For example, VR-l Acid is a mixture of dicarboxylic acids and has an average molecular Weight of about 700, is a liquid at 77 F., and has an acid number of about 150 and an iodine number of about 36. It contains an average of thirty-six carbon atoms per molecule.

Another preferred polycarboxylic acid comprises a mixed acid being marketed commercially under the trade name of Empol 1022. This dimer acid is a dilinoleic acid and is represented by the following general formula:

This acid is a viscous liquid, having an apparent molecular weight of approximately 600. It has an acid value of 180- 192, an iodine value of -95, a. saponification value of 185-195, a neutralization equivalent of 290-310, a refractive index at 25 C. of 1.4919, a specific gravity at 15.5/l5.5 C. of 0.95, a flash point of 530 F., a fire point of 600 F., and a viscosity at C. of 100 centistokes. The above-mentioned Dimer Acid is substantially the same as Empol 1022.

While the polycarboxylic acid may be employed, advantages appear to be obtained in some cases when using anhydrides thereof and particularly alkenyl-acid anhydrides. A preferred alkenyl-acid anhydride is dodecenylsuccinic anhydride. Other alkenyl-acid anhydrides include butenyl-succinic anhydride, pentenyl-succinic anhydride, hexenyl-succinic anhydride, heptenyl-succinic anhydride, octenyl-succinic anhydride, nonenyl-succinic anhydride, decenyl-succinic anhydride, undecenyl-succinicanhydride, tridecenyl-succinic anhydride, tetradecenyl-succinic anhydride, pentadecenyl-succinic anhydride, hexadecenyl-succinic anhydride, heptadecenyl-succinic anhydride, octadecenyl-succinic anhydride, nonadecenyl-succinic anhydride, eicosenyl-succinic anhydride, etc. While the alkenylsuccinic anhydrides are preferred, it is understood that the alkyl-succinic anhydrides may be employed, the alkyl groups preferably corresponding to the alkenyl groups hereinbefore specifically set forth. Similarly, While the aliphatic succinic anhydrides are preferred, it is understood that the anhydrides and particularly aliphatic-substituted anhydrides of other acids may be employed including, for example, adipic anhydride and particularly aliphatic adipic anhydrides, glutaric anhydride and particularly aliphatic glutaric anhydrides, etc.

When a monocarboxylic acid is utilized in preparing the ester, the salt of the novel composition of matter is believed to comprise one or a mixture of salts illustrated by the following formulas:

where R is alkyl or alkenyl containing from 1 to about 50 carbon atoms and preferably from 8 to about 40 carbon atoms, and R, R R R and R have the designatrons previously set forth.

Any suitable monocarboxylic acid may be used and will range from acetic acid to pentacontyl acid, as well as corresponding acids containing unsaturation in the chain. It is understood that the acid may be of straight chain or it may contain branching in the chain. Conveniently the acid used is a fatty acid. Illustrative preferred acids include caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behenic, lignoceric, cerotic, etc., decylenic, stillingic, dodecylenic, palmitoleic, oleic, ricinoleic, petroselinic, vaccenic, linoleic, linolenic, eleostearic, licanic, parinaric, gadoleic, arachidonic, cetoleic, erucic, selacholeic, etc. However, it is understood that any other suitable monocarboxylic acid may be used in forming the ester.

As hereinbefore set forth the ester will be a monoester, diester or mixture thereof. It also may comprise the half ester or the full ester. It is expected that the final additive Will comprise a mixture of salts.

The ester is formed in any particular manner and will comprise the interraction of one: or both hydroxyalkyl groups of the phosphinic acid with one or more of the hydroxyl radicals of the carboxylic acid. As hereinbefore set forth it also may include the formation of polymeric 7 compounds. The reaction may be effected in the absence or presence of a solvent. Generally the use of solvent is preferred and any suitable solvent may be employed. The reaction conveniently is effected by refluxing the mixture of reactants, with the liberation and removal of water formed during the reaction. The temperature of the reaction will be above 80 C. and will be within the range of from about 80 C. and preferably from about 120 C. to 240 C. or higher. The exact temperature will depend upon the particular solvent employed. For example, with benzene as the solvent, the temperature will be of the order of 80 C., with toluene the temperature will be of the order of 121 C., and with xylene the order of 149- 160 C. Other solvents include cumene, naphtha, Decalin, etc. Any suitable amount of the solvent may be employed but preferably should not comprise a large excess because this will tend to lower the reaction temperature and slow the reaction. Water formed during the reaction may be removed in any suitable manner including, for example, by operating under reduced pressure, by removing an azeotrope of water-solvent, by distilling the reaction product at an elevated temperature, etc. A higher temperature may be utilized in order to remove the water as it is being formed. The time of reaction is suflicient to eifect the desired reaction and, in general, will range from about four to forty hours or more.

The salt may be recovered as a solid or viscous liquid and when desired may be formed as a solution in a suitable solvent. The solvent will be selected with reference to the use to be made of the salt. When the salt is to be used as an additive to hydrocarbon oil, a suitable solvent includes aromatic hydrocarbon and particularly benzene, toluene, ethylbenzene, cumene, etc., or paraffin hydrocarbon including hexane, heptane, octane, nonane, etc., or mixtures containing one or both of these types of hydrocarbons such as naphtha, gasoline, kerosene, etc.

As hereinbefore set forth, the salt of the present invention is used as an additive in hydrocarbon oil, grease or synthetic lubricant. These undergo oxidative, thermal and/ or other deterioration. The hydrocarbon oil includes gasoline, naphtha, kerosene, jet fuel, lubricating oil, diesel fuel, fuel oil, residual oil, etc. In lubricating oil, the additive functions as a lubricity or extreme pressure agent. In addition, the additive serves as a flame-proofing agent, detergent-dispersant, peroxide decomposer, corrosion inhibitor, rust inhibitor, etc.

The salt of the present invention is advantageously used as an additive in lubricating oil. The lubricating oil may be of natural or synthetic origin. The mineral oils include those of petroleum origin and are referred to as motor lubricating oil, railroad type lubricating oil, marine oil, differential oil, diesel lubricating oil, gear oil, cylinder oil, specialty products oil, cutting oil, drawing oil, metal Working lubricant, etc. Other oils include those of animal, marine or vegetable origin.

The lubricating oils generally have a viscosity within the range of from 10 SUS at 100 F. to 1000 SUS at 210 F. (SAE viscosity numbers include the range from SAE 10 to SAE 160). The petroleum oils are obtained from paraflinic, naphthenic, asphaltic or mixed base crudes. When highly paraffinic lubricating oils are used, a solubilizing agent also may be used if of advantage.

Synthetic lubricating oils are of varied types including aliphatic esters, polyalkylene oxides, silicones, esters of phosphoric and silicic acids, highly fluorine-substituted hydrocarbons, etc. Of the aliphatic esters di-(Z-ethylhexyl)-sebacate is being used on a comparatively large commercial scale. Other aliphatic esters include dialkyl azelates, dialkyl suberates, dialkyl pimelates, dialkyl adipates, dialkyl glutarates, etc. Specific examples of these esters include dihexyl azelate, di-(2-ethylhexyl)- azelate, di-3,5,5-trimethylhexyl glutarate, di-3,5,5-trimethylpentyl glutarate, di-(2-ethylhexyl)-pimelate, di (2-ethylhexyl)- adipate, triamyl tricarballylate, pentaerythritol tetracapro ate, dipropylene glycol dipelargonate, 1,5-pentane-dio1-di- (Z-ethylhexanonate), etc. The polyalkylene oxides include polyisopropylene oxide, polyisopropylene oxide diether, polyisopropylene oxide diester, etc. The silicones include methyl silicone, methylphenyl silicone, etc., and the silicates include, for example, tetraisooctyl silicate, etc. The highly fluorinated hydrocarbons include fluorinated oil, perfiuorohydrocarbons, etc.

Additional synthetic lubricating oils include (1) neopentyl glycol esters in which the ester group contains from three to twelve carbon atoms or more, and particularly neopentyl glycol propionates, neopentyl glycol butyrates, neopentyl glycol caproates, neopentyl glycol caprylates, neopentyl glycol pelargonates, etc., (2) trimethylol alkane esters such as the esters of trimethylol ethane, trimethylol propane, trimethylol butane, trimethylol pentane, trimethylol hexane, trimethylol heptane, trimethylol octane, trimethylol nonane, trimethylol decane, trimethylol undecane, trimethylol dodecane, etc., and particularly triesters in which the ester portions each contain from three to twelve carbon atoms and may be selected from those hereinbefore specifically set forth in connection with the discussion of the neopentyl glycol esters, (3) complex esters composed of dibasic acids and glycols, especially neopentyl, neohexyl, etc., glycols further reacted with monobasic acids or alcohols to give lubricants of viscosi ties at 210 F. of from four to twelve centistokes or higher, and (4) tricresylphosphate, trioctylphosphate, trinonylphosphate, tridecylphosphate, etc., as well as mixed aryl and alkyl phosphates.

The present invention also is used in the stabilization of greases made by compositing one or more thickening agents with an oil of natural or synthetic origin. Metal base synthetic greases are further classified as lithium grease, sodium grease, calcium grease, barium grease, strontium grease, aluminum grease, etc. These greases are solid or semi-solid gels and, in general, are prepared by the addition to the lubricating oil of hydrocarbon soluble metal soaps or salts of higher fatty acids as, for example, lithium stearate, calcium stearate, aluminum naphthenate, etc. The grease may contain one or more thickening agents such as silica, carbon black, talc, organic modified Bentonite, etc., polyacrylates, amides, polyamides, aryl ureas, methyl N-n-octadecyl terephthalomate, etc. Another type of grease is prepared from oxidized petroleum wax, to which the saponifiable base is combined with the proper amount of the desired saponifying agent, and the resultant mixture is processed to a grease. Other types of greases in which the features of the present invention are usable include petroleum grease, whale grease, Wool grease, etc., and those made from inedible fats, tallow, butchers waste, etc.

Oils of lubricating viscosity also are used as transmission fluids, hydraulic fluids, industrial fluids, etc., and the novel features of the present invention are used to further improve the properties of these oils. During such use the lubricity properties of the oil are important. Any suitable lubricating oil which is used for this purpose is improved by incorporating the additive of the present invention.

Oils of lubricating viscosity also are used as cutting oils, rolling oils, soluble oils, drawing compounds, etc. In this application, the oil is used as such or as an emulsion with water. Here again, it is desired that the oil serves to lubricate the metal parts of saws, knives, blades, rollers, etc., in addition to dissipating the heat created by the contact of the moving metal parts.

Oils of lubricating viscosity also are used as slushing oils. The slushing oils are employed to protect finished or unfinished metal articles during storage or transportation from one area to another. The metal articles may be of any shape or form including steel or other metal sheets, plates, panels, coils, bars, etc., which may comprise machine parts, engines, drums, piston rings, light arms, etc., as well as farm machinery, marine equipment, parts for military or other vehicles, household equipment,

factory equipment, etc. A coating which may be visible to the eye, or not, as desired, covers the metal part and protects it from corrosion.

The salt of the present invention also is useful as an additive in fuel oil to prevent sediment formation. The fuel oil is marketed under various names including fuel oil, furnace oil, burner oil, range oil, diesel oil, etc. In such use the salt prevents sediment formation which may be due to oxidation, thermal reactions, etc., and also serves to disperse any sediment which is formed in the oil. The salt also serves as a rust or corrosion inhibitor, as well as retarding discoloration of the oil.

In another embodiment the salts of the present invention possess insecticidal properties with good inner therapeutic action. They may be employed against many types of mites and insects such, as for example, Corausius larvae, Cotoneaster aphid, apple aphid, black bean aphid, pea aphid, etc. The salt, preferably as a solution in a suitable solvent, may be used for the control of various larvae, mites, insects as flour beetle, Mexican bean beetle, black carpet beetle, milkweed bug, German cockroaches, southern army worms, mealy bug, sow bug, citrus red spider, greenhouse red spider, various mosquitoes, yellow fever mosquito, malarial mosquito, houseflies, etc.

In addition the salt may find use in metal priming compositions, as ion-exchange resins, complexing agents for certain cations, and other uses in which various phosphorus-containing compounds are employed.

The concentration of the salt to be employed as an additive will depend upon the particular substrate in which it is to be used. In general, the additive is used in a concentration of from about 0.001% to about 25 by weight of the substrate and more specifically Within the range of from 0.01% to about 5% by weight of the substrate. When used in conventional lubricating oil, the additive generally may be employed in a concentration of from about 0.01% to about 2% by weight of the oil. When used in lubricating oil for more severe operations, such as hypoid gear oil, the additive is used in a concentration of from about 1% to about 20% or more by weight of the oil. In general, substantially the same range of additive concentration is employed when the oil is used as transmission fluid, hydraulic fluid, industrial fluid, etc. When the oil is used in the formulation of a grease, the additive is used in a concentration of from about 0.5% to 5% by weight of the oil. When used in cutting oil, rolling oil, soluble oil, drawing compound, etc., the additive may be used in a concentration of from about 0.1% to about by weight of the oil. When used in slushing oil, the additive may be used in a concentration of from about 0.1% to about by weight or more of the oil.

It is understood that the additive of the present invention may be used along with other additives incorporated in the organic substrate. The other additives will depend upon the particular organic substrate. For example, in lubricating oil, the additional additives may comprise one or more of viscosity index improvers, pour point depressors, anti-foam additives, detergents, corrosion inhibitors, additional antioxidants, etc. Preferred additional antioxidants are of the phenolic type and include teritarybutylcatechol, 2,6-ditertiarybutyl-4-methylphenol, 2,4- dimethyl-G-tertiarybutylphenol, etc., 2-tertiarybutyl-4- methoxyphenol, Z-tertiary-4-ethoxyphenol, 3,3',5,5'-tetratertiarybutyl-dihydroxydiphenylmethane, etc.

The salt of the present invention is an emulsifying agent and therefore will serve to emulsify Water and oil of lubricating viscosity for use as lubricating oil, slushing oil, cutting oil, rolling oil, soluble oil, drawing compound, etc. When desired, an additional emulsifying agent may be employed. Any suitable emulsifying agent can be used, including alkali metal, sulfonates of petroleum sulfonic acids, mahogany sulfonates, naphthenic acids, fatty acids, etc., fatty alcohol sulfonates, pentaerythritol oleates, laurates, etc. The amount of water used in the emulsified oils will depend upon the par- I0 ticular use of the emulsion and may range from 0.25% to 50% or even up to 98% by weight of the composition. The additive of the present invention is incorporated in the substrate in any suitable manner and preferably is suitably agitated with or otherwise mixed in the substrate in order to obtain intimate dispersion of the additive in the substrate. When the substrate comprises a mixture of two or more components, the additive of the present invention may be commingled with one of the components prior to mixing with the remaining component or components of the substrate.

The following examples are introduced to illustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.

EXAMPLE I The salt of this example was prepared by mixing and heating bis-(hydroxymethyl)-phosphinic acid and a mixed amine comprising tertiary alkyl amines containing from 18 to 22 carbon atoms per molecule. The mixed amines used in this example are marketed commercially under the name of Primene JM-T. The properties of this amine have been set forth hereinbefore. The salt was prepared by commingling, with stirring, 27.2 g. (0.2 mole) of bis-(hydroxymethyl)-phosphinic acid and 67 g. (0.2 mole) of the mixed amines. The reaction was exothermic. However, in order to insure completion of the salt formation, the reaction mixture Was heated to C. This resulted in a very viscous product. In order to prepare a more fluid solution for easier handling, 94 g. of a commercial lubricating oil was added and the mixture was stirred and heated. This resulted in a homogeneous solution of 50% by weight concentration of active ingredient when heated.

EXAMPLE II The salt of this example is a tertiary amine salt of bis-(hydroxymethyl)-phosphinic acid. The tertiary amine used in this example is dimethyl hydrogenated tallow amine and is marketed commercially as Armeen DMHTD. The salt was prepared by commingling 34 g. (0.25 mole) of bis-(hydroxymethyl)-phosphinic acid and 73 g. (0.25 mole) of the dimethyl octadecyl amine, the mixture was stirred and heated on a steam bath, resulting in the formation of the salt as a white precipitate.

EXAMPLE III The salt of this example is the dimethyl octadecyl salt of an ester of bis,(hydroxymethyl)-phosphinic acid. The salt was formed in the manner as described in Example II. Xylene was added to the reaction mixture while refluxing. This formed a homogeneous solution, to which 70.5 g. of dodecenyl-succinic anhydride Was added. Heating and refluxing of this mixture was continued with the temperature of refluxing ranging from to 210 C. A total of 5.2 cc. of Water was collected from the reaction. The reaction mixture was heated at C. under Water pumped vacuum to remove the xylene and to recover the salt as the residue. The salt contained 4.18% by weight of phosphorus.

EXAMPLE IV The salt of this example is prepared by commingling, With stirring and heating to 110 (3., equal mole proportions of bis-(hydroxyethyl)-phosphinic acid and lauryl amine. The salt is recovered as a viscous liquid.

EXAMPLE V The salt of this example is prepared by commingling one mole proportion of bis-(hydroxybutyl)-phosphinic acid with one mole proportion of N-beta-pentadecyl-1,3- propylenediamine, marketed as Duomeen L-15. The reaction mixture is stirred and heated to 120 C. for 3 hours to form the salt as a viscous liquid.

11 EXAMPLE VI The salt of this example is prepared by first reacting bis-(hydroxymethyl)-phosphinic acid with diethylhexadecyl amine and then reacting with dodecenyl- 12 Run No. 2 is a run made using another sample of the Plexol to which has been added 4% by weight of the solution prepared as described in Example I (2% by weight of active ingredient).

NOTE.S=Seizure.

succinic anhydride. The salt is formed by commingling and heating to 110 C. equal mole proportions of the bis-(hydroxymethyl)-phosphinic acid and the diethylhexadecyl amine, followed by refluxing at a temperature of 210 C. with 2 mole proportions of dodecenyl-succinic anhydride in the presence of xylene solvent. The Water liberated in the reaction is collected. The xylene solvent is removed by vacuum distillation, and the salt is recovered as the residue.

EXAMPLE VII As hereinbefore set forth the salt of the present invention is of special utility as an additive in lubricating oil. One method of evaluating lubricating oils is by the Falex machine. This procedure is described in detail in a book entitled Lubricant Testing authored by E. G. Ellis and published by Scientific Publications (Great Britain) Limited, 1953, pages l50154. Briefly, the Falex machine consists of a rotating pin which runs between two V- shape bearings which are spring loaded against the pin and provided with means for varying the load. The oil to be tested is poured into a metal trough in which the pin and bearings are partly submerged. The machine was operated for five minutes each at 250 and 500 pound loads and then for forty-five minutes at 750 pound load. The data collected includes the temperature of the oil and the torque at each of the loads, as well as the wear which is determined by a ratchet wheel arrangement in which the teeth are advanced in order to maintain the desired load. Each tooth is equivalent to approximately From the data in the above table it will be seen that 15 the dioctyl sebacate without additive (Run No. 1) underwent seizure at a load of 750 pounds. In contrast, seizure conditions for the sample of the dioctyl sebacate containing the additive of the present invention was 1750 pounds.

EXAMPLE VIII Another series of evaluations were made in the same manner as described in Example VII, except that the lubricating oil was a mineral oil marketed commercially by A. H. Carnes Company as Carnes 340 White Oil.

5 Typical specifications of this oil include the following:

Distillation range, F 740-975 Specific gravity at 60 F. 0.8836 Viscosity:

At 100 F. 360

At 210 F. 52.2

Flash point, CIC, F. 440

Pour point, F 20 Refractive index at 68 F. 1.4805

Saybolt color +30 Run No. 3 in the following table is a run using the white oil not containing an additive and thus is the blank or control run.

Run No. 4 is a run using another sample of the white oil to which has been added 4% by weight of the salt solution prepared as described in Example I (2% by weight of active ingredient).

NOTE.S= Seizure.

0.000022 inch Preferred additives are those which impart low temperature, low torque and low wear to the oil.

In another series of tests the machine was operated for five minutes at each load from 250 pounds to seizure at 250 pound increments. The maximum load and the time in minutes at this load to seizure are reported, as well as the temperature of the oil. In this case the higher v temperature is preferred because it means that the oil is operating satisfactorily at a higher temperature.

The lubricating oil used in this example is dioctyl sebacate synthetic lubricating oil marketed under the trade name of Plexol 201.

Run No. 1 in the following table is a run made using the Plexol not containing an additive and thus is the blank or control run.

Here again it will be seen that the oil without additive (Run No. 3) underwent seizure at a small load which, in this case, was 425 pounds. In contrast, the white oil containing the additive of the present invention did not undergo seizure until a load of 1500 pounds.

EXAMPLE IX The salt of the ester, prepared as described in Example III also was evaluated in Plexol in the same manner as described in Example VII.

Run No. 1 in the following table is a run using the Plexol without additive and is a repeat of Run No. 1 in Example VII.

5 Run No. 5 is a run made using another sample of the Plexol to which has been added 2% by weight of the salt prepared as described in Example III.

TABLE III Seizure conditions Temperature, F. Torque, lbs. Wear, teeth Tempera- 250 500 750 250 500 750 250 500 750 Load Time ture,F.

Run No NOTE.S Seizure.

EXAMPLE X The salt prepared as described in Example III was also evaluated in mineral oil in the same manner as described 1 4 mercial fuel oil and tested in A.S.T.M.-C.F.R. Coker Test Method D-1600, using 6 p.p.h. fuel flow at a preheated temperature of 400 F. and a tube temperature of 500 F. After 300 minutes, the differential pressure was 4.5 in. Hg. By contrast the uninhibited oil reached a diiferential pressure of 25 in. Hg in 87 minutes.

I claim as my invention: 1. An organic composition selected from the group consisting of hydrocarbon fuels, greases, and lubricating in Example VH1. oils, normally subject to oxidative deterioration contain- Run Na 3 in the following table is a run using the ing, as an inhibitor against said deterioration, an amine white oil not containing an additive and is a repeat of Salt of bis-(hydfoxyalkyn-phosphillic acid aliphatic R N 3 inExample L monocarboxylic and dicarboXylic acid esters thereof,

Run No. 6 is a run using another sample of the white wherein the alkyl group contains from 1-6 carbon atoms. oil to which has been added 2% by weight of the salt 2. The composition of claim 1 wherein the organic maprepared as described in Example III. terial is a hydrocarbon fuel.

TABLE IV Seizure conditions Temperature, F. Torque, lbs. Wear, teeth Tempera- 250 500 750 250 500 750 250 500 750 Load Time turc, F.

Run No 3 172 aso-s 5-6 -s 0 s 425 0.1 275 N o TE.S Seizure.

Here again it will be seen that the additive of the pres- 3. The composition of claim 1 wherein the organic ent invention was efiective in improving the properties of material is a lubricating oil. the lubricating oil. 4. The composition of claim 3 wherein the lubricating EXAMPLE XI 30 oil is dioctyl sebacate.

The salt prepared as described in Example IV is used 5. The composition of claim 1 wherein said salt is a in a concentration of 1% by weight as an additive in salt Of aliphatic amine containing from 4 t0 carbon grease. The additive is incorporated in a commercial atoms 311d Y Y Y )"P P acid wherein Mid-Continent lubricating oil having an SAE viscosity the alkyl g p Contains from 1 t0 6 a l at m of 20. Approximately 92% of the lubricating oil then 5 6. The composition of claim 1 wherein said salt is a i i d i h approximately 3% b i h of li hi salt of tertiary amine containing from 8 to 40 carbon stearate. The mixture is heated to about 450 F. with atoms and ester of Y Y Y )P p acidconstant agitation. Subsequently, the grease is cooled, The composition of Claim 1 wherein d lt i while agitating, to approximately 248 F., and then the salt of eicosyl amine and bis-(hydroxymethyl)-phosphinic grease is further cooled slowly to room temperature. 40 acid.

The stability of the grease is tested in accordance with References Cited ASTM D-942 Method, in which method a sample of the grease is placed in a bomb and maintained at a tempera- UNITED STATES PATENTS ture of 212 F. Oxygen is charged to the bomb, and the 2,279,502 4/1942 Dickey et a1 260 501.21 time required for a drop of five pounds pressure 1s taken 2,982,727 5/1961 Pattenden et a1. 252 32'5 as the Inductm Pemd- 3,001,938 9/1961 Morway et a1. 252-425 EXAMPLE XII 3,157,694 11/1964 Harwood 2s2 32.s

The salt prepared as described in Example VI is used as an additive in fuel oil and serves to prevent sediment DANIEL E WYMAN p i Examiner formation therein. The salt is incorporated in the fuel 011 in a concentration of 0.01% by weight. This not only IRVING VAUGHN Assistant m I serves to retard sediment formation but also serves to disperse any sediment which may be formed in the oil. US. Cl. X.R'..

EXAMPLE X111 44-66, 71, 72; 2528.1, 78, 351, 389, 400; 2602.1;

The salt prepared as described in Example XIII was dissolved at 0.001% by weight concentration in No. 1 com- 

